Method of equipping a tool handle or hand grip with a tough adherent protective layer with enhanced gripping properties

ABSTRACT

A method of providing a tool handle or the like hand grip with a tough protective strong-gripping layer by shrinking and bonding a sleeve of heat-reactive thermoplastic material thereto.

[ Feb. 13, 1973 United States Patent 91 Plummer sm m m mm MAW G s$w mTwmAu rT kSW D RE9 flfi NH Um 4 7 7 1 m m w 2,985,209 5/1961 Novelo3,072,517 3,359,943 3,470,046 3,578,825

.l56/84 X Briggs et a1. 9/1969 Verdin 5/1971 l/l963 Gaylord............12/1967 A. Plummer, 3546 [76] Inventor: Walter Crownridge Drive, ShermanOaks, Calif.

[22] Filed: Sept. 18, 1970 Primary ExaminerEdward G. Whitby [211 pp No73 492 Attorney-Sellers and Brace [57] ABSTRACT A method of providing atool handle or the like hand grip with a tough protectivestrong-gripping layer by shrinking and bonding a sleeve of heat-reactivethermoplastic material thereto.

[52] U.S. Cl.

..l56/85, 16/110 R, 145/61 R,

[51] Int. 27/10 [58] Field 0fSearch....156/84, 85, 86, 294, 213, 295;

16/110, 116 R; 306/32; 145/61 R, 61 C 6 Claims, 5 Drawing FiguresPATENTED FEB 1 31915 INVENTOR 14440752 A Pia/144465 METHOD OF EQUIPPINGA TOOL HANDLE OR HAND GRIP WITH A TOUGH ADHERENT PROTECTIVE LAYER WITHENHANCED GRIPPING PROPERTIES This invention relates to tool handles andthe like hand grips and more particularly to an improved method ofpermanently assembling thereto a protective layer of thermoplasticmaterial providing greatly enhanced gripping and safety properties.

Tool handles and hand grips for a wide variety of appliances, sportinggoods, tools and other devices have need for a protective finish havingnumerous characteristics not satisfactorily satisfied by the techniquesand proposals heretofore made. Not only is it highly important that ofinnumerable implements, such as axes, hammers, golf clubs, bats, etc.,to name but a few, the gripping surface be highly resistant to slippagewhen gripped but it must be resistant to abrasion, corrosion, attack bythe elements, withstand a wide variety of abuses and provide reliableprotection against slippage, loss of control, malfunctioning, electricalshocks and meet other well known requirements.

The simple, quickly performed method and technique characterizing thisinvention meets the foregoing and other exacting and widely variantneeds to a highly satisfactory degree by utilizing the highlyadvantageous properties of heat reactive thermoplastic tubing. Thismaterial is readilyavailable on the market in any desired diameter andwall thickness, and possesses a shrinkage coefficient of at leastpercent in most embodiments thereof. This material quickly shrinks uponthe application of heat into snug fitting conformity with any underlyingsurface falling within the latitude of its shrinkage capabilities.Sleeving of appropriate size is selected for loose fitting assembly overthe tool handle to be encapsulated following completion of which heat isapplied to its exterior adequate to soften the material. therebyautomatically releasing internal stresses and allowing the material toshrink until snugly bearing against the juxtaposed underlying surface.Desirably, the ends of the sleeve project beyond the adjacent ends ofthe handle with the result that the application of heat causes the endsto curl inwardly into snug conformity with the handle ends. Desirably, alayer of adhesive is applied between the handle surface and the interiorof the sleeve thereby further strengthening and reinforcing the finalassembly.

It is therefore an important object of the invention to provide animproved method of providing tool handles and other hand grips with animproved strong-adherent protective covering with pronouncedanti-slipping characteristics.

Another object of the invention is the provision of an improvedtechnique for finishing tool handles and hand grips with a non-slip,non-conductive, permanent protective cover.

These and other more specific objects will appear upon reading thefollowing specification and claims and upon considering in connectiontherewith the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of theinvention is illustrated:

FIG. I is a cross sectional view showing one suitable means for applyingadhesive to the interior of the invention hand grip sleeve; 7

FIG. 2 is an end view on an enlarged scale taken from the left hand endof FIG. 1;

FIG. 3 is an enlarged cross sectional view of the sleeve with theapplied adhesive;

FIG. 4 is a side view, partly in section, of a typical tool handle inthe process of having the protective sleeve shrunk thereagainst; and

FIG. 5 is a cross sectional view through a typical tool handle ofnon-cylindrical cross-section in its final assembled condition.

Referring initially more particularly to FIG. 1, there is shown a lengthof the invention heat reactive thermoplastic sleeving l0 telescoped overa spray nozzle 1 l which is supplied through hose 12 with any suitableadhesive material. This adhesive flows through passage 13 of the nozzleand through its discharge ports 14 onto the interior surface of sleeving10. Typically, the tubing is inserted over nozzle 11 until properlypositioned for the deposit of the adhesive layer 16 onto'the innermostend of the sleeve. The sleeve is then gradually withdrawn from thenozzle so as to deposit a layer 16 of adhesive of uniform thickness.

After the sleeve has been coated with adhesive it is assembled to a handgrip by telescoping it over one end of the tool handle, such as thehandle 18 of a screw driver bit 19. In the usual case, sleeve 10 has alength slightly in excess of the handle being encapsulated so that itsends 20,20 project slightly beyond the handle ends. The assemblyoperation is accomplished quickly and easily and without displacing theadhesive owing to the slightly larger diameter of the sleeve. The partsare then bonded together by the simple expedient of applying moderateheat, such as from the hot air nozzle 22 to all parts of sleeve 10. Itis desirable that the hot air nozzle be moved so as to direct hot airagainst and soften all parts of the sleeve. An air temperature of -200is quite satisfactory although the operating temperature depends uponhow close the air nozzle is held and how quickly it is moved from placeto place over the sleeve. All that is required is sufficient heat tosoften the sleeve material whereupon it quickly shrinks and draws verysnugly against the underlying surface. Likewise, the opposite ends ofthe sleeve collapse and curl about the adjacent ends of the handle, asis clearly indicated in FIG. 4.

In many instances the tool handle is provided with a non-cylindricalexterior surface to enhance its gripping characteristics. One of themany typical non-cylindrical configurations is shown in FIG. 5 whereinit will be noted that the protective thermoplastic layer has shrunk intohigh fidelity configuration with the underlying surface of the handle towhich it is strongly bonded by the adhesive layer 16.

While the particular method of equipping a tool handle or hand grip witha tough adherent protective layer herein shown and disclosed in detailis fully capable of attaining the objects and providing the advantageshereinbefore stated, it is to be understood that it is merelyillustrative of the presently preferred embodiment of the invention, andthat no limitations are intended to the details of construction ordesign herein shown other than as defined in the appended claims.

I claim:

1. That method of providing a tool handle, hand grip or the like with anon-conductive high-grip protective layer which comprises: telescoping asleeve of heat reactive thermoplastic material having a length greaterthan the length of the hand grip and a high shrinkage coefficient overthe hand grip of the handle to be protected with at least one endthereof projecting slightly beyond the end of said hand grip, andsubjecting the assembly to heat adequate to shrink said sleeve into asnug fit with the juxtaposed surface of the handle with said projectingend of said sleeve curled snugly against 4. That method defined in claim1 characterized in the step of applying a layer of adhesive to theinterior surface of said sleeve prior to telescoping the same over thehandle.

5. That method defined in claim 4 characterized in the step of applyingsaid layer of adhesive to said sleeve by jetting adhesive onto the innersurface of the sleeve progressively from one end thereof toward theother end of the sleeve.

6. That method defined in claim 1 characterized in telescoping saidsleeve of heat reactive material over a handle having a non-cylindricalouter surface, and applying heat to heat shrink said sleeve into snugconformity with said non-cylindrical surface.

1. That method of providing a tool handle, hand grip or the like with anon-conductive high-grip protective layer which comprises: telescoping asleeve of heat reactive thermoplastic material having a length greaterthan the length of the hand grip and a high shrinkage coefficient overthe hand grip of the handle to be protected with at least one endthereof projecting slightly beyond the end of said hand grip, andsubjecting the assembly to heat adequate to shrink said sleeve into asnug fit with the juxtaposed surface of the handle with said projectingend of said sleeve curled snugly against the juxtaposed end of said handgrip.
 2. That method defined in claim 1 characterized in applying alayer of Adhesive between the surface of the handle and the innersurface of said sleeve of heat reactive material.
 3. That method definedin claim 1 characterized in the step of applying a layer of adhesive tothe surface of one of the aforesaid two components before heating saidheat reactive material to shrink it against the surface of said handle.4. That method defined in claim 1 characterized in the step of applyinga layer of adhesive to the interior surface of said sleeve prior totelescoping the same over the handle.
 5. That method defined in claim 4characterized in the step of applying said layer of adhesive to saidsleeve by jetting adhesive onto the inner surface of the sleeveprogressively from one end thereof toward the other end of the sleeve.